vhost: arrange struct fields for better cache sharing

The ifname[] field takes so much space, that it seperates some frequently
used fields into different caches, say, features and broadcast_rarp.

This patch moves all those fields that will be accessed frequently in Rx/Tx
together (before the ifname[] field) to let them share one cache line.

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Huawei Xie <huawei.xie@intel.com>
Tested-by: Rich Lane <rich.lane@bigswitch.com>

diff --git a/lib/librte_vhost/vhost-net.h b/lib/librte_vhost/vhost-net.h
index 162ad04..41a3ccf 100644 (file)
--- a/lib/librte_vhost/vhost-net.h
+++ b/lib/librte_vhost/vhost-net.h
@@ -128,16 +128,16 @@ struct virtio_net {
        int                     vid;
        uint32_t                flags;
        uint16_t                vhost_hlen;
+       /* to tell if we need broadcast rarp packet */
+       rte_atomic16_t          broadcast_rarp;
+       uint32_t                virt_qp_nb;
+       struct vhost_virtqueue  *virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];
 #define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
        char                    ifname[IF_NAME_SZ];
-       uint32_t                virt_qp_nb;
        uint64_t                log_size;
        uint64_t                log_base;
        struct ether_addr       mac;
 
-       /* to tell if we need broadcast rarp packet */
-       rte_atomic16_t          broadcast_rarp;
-       struct vhost_virtqueue  *virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];
 } __rte_cache_aligned;
 
 /**